Coupling for a movable furniture part

ABSTRACT

The invention relates to a retraction device for a movable piece of furniture, having a pulling means windable on a roll, wherein an electric motor is provided for driving the roll, and having a coupling for releasably connecting the movable piece of furniture to the electric drive, having a first coupling part for fastening to the movable piece of furniture and a second coupling part connected to the pulling means, the first coupling part having an opening for at least the partial acceptance of the second coupling part, a locking mechanism being provided by which the first coupling part can be connected to the second coupling part in at least two different positions, the second coupling part being located at different depths in the opening in the two different positions.

The present invention concerns a coupling for releasably connecting a movable furniture part to a drive, comprising a first coupling portion intended for fastening to the movable furniture part and a second coupling portion intended for fastening to the drive, wherein the first coupling portion has an opening for at least partially receiving the second coupling portion.

Couplings of that kind suffer from the problem that, by virtue of installation tolerances in respect of the drive or the movable furniture part in the body or carcass of the piece of furniture, it is not always possible to predict how far the second coupling portion can be introduced into the opening in the first coupling portion. Thus for example the drive or the movable furniture part (and therewith the corresponding coupling portions) can be disposed at differing depths in the furniture body or carcass, depending on the respective installation situation.

The object of the invention is to develop a coupling of the general kind set forth, such that it involves compensation at least in respect of the depth tolerance in relation to the arrangement of the first and second coupling portions.

That object is obtained by a coupling having the feature of claim 1.

The provision of a locking mechanism which ensures locking of the two coupling portions relative to each other for different depths of insertion of the second coupling portion into the first coupling portion achieves the depth tolerance compensation required in accordance with the statement of object.

In a preferred embodiment of the coupling it is provided that the locking mechanism releases the connection between the first and second coupling portions upon the attainment of a predetermined separation force. In that case it is desirable if the predetermined separation force is of equal magnitude for the at least two different positions. That provides that use of the coupling does not involve any noticeable dependencies on the actual installation position.

The locking mechanism can have for example two clamping jaws which are biased relative to each other by a force storage means (for example springs) and which clamp the second coupling portion fast in the locking condition. If the separation force acting on the two coupling portions exceeds the force exerted on the clamping jaws by the force storage means, the locking mechanism is opened. That leads to uncoupling of the drive and the movable furniture part.

To facilitate insertion of the second coupling portion into the opening in the first coupling portion it can be provided that a pin for insertion into the opening is arranged on the second coupling portion. In that case the pin can have at least two axially mutually spaced latching positions for the clamping jaws.

The two mutually spaced latching positions allow locking of the two coupling portions in the two different positions of the first and second coupling portions relative to each other.

In that case each of the latching positions can have at least one groove, into which the clamping jaws engage in the locking condition.

Per se there can also be provided two or more grooves per latching position so that the clamping jaws engage into two or more grooves in each latching position.

If the separation force for the at least two different positions of the coupling portions is to be of the same magnitude it must however be guaranteed that the number of grooves into which the clamping jaws engage in the locking condition is the same for each of the latching positions.

Per se it can be provided that the latching positions are markedly spaced from each other over the axial extent of the pin, and therefore that there is a non-grooved axial region of the pin between the grooves of the respective latching positions. It will be noted however that this is disadvantageous insofar as that only affords a stepwise compensating option for depthwise positioning of the two coupling portions relative to each other.

It is therefore particularly preferably provided that the pin has a plurality of adjacent grooves over its axial extent. In this case therefore there are non-grooved intermediate spaces between the individual latching positions. If it is provided that the clamping jaws respectively engage into a groove in the locking condition, a dedicated latching position is implemented by each groove. That affords an approximately stepless compensating option, in relation to the depthwise tolerance.

In order to permit the pin to be captured in a direction at a right angle to the direction of insertion (that is to say in the case of an eccentric approach), it can be provided that a funnel is to be arranged in front of the opening of the first coupling portion.

Per se the coupling according to the invention is suitable for a wide range of different drives. It will be noted however that it is particularly preferably provided that the second coupling portion is connectable to the pulling means of a retraction device.

The present invention further concerns a retraction device for a movable furniture part having a pulling means which can be wound on a roller, wherein there is provided an electric motor for driving the roller, wherein the retraction device is distinguished by a second coupling portion, connected to the pulling means, of a coupling in accordance with one of the aforementioned embodiments.

Such a retraction device can be provided with a housing, in which the roller and the electric motor are arranged. In that case it is advantageous if the housing has in the unwinding region of the roller a window which is substantially larger than the cross-section of the pulling means. That provides that the pulling means can relatively freely move in the unwinding region in a direction in orthogonal relationship to the unwinding direction (and thus in orthogonal relationship to the direction of movement of the movable furniture part), which provides for compensation in relation to installation tolerances at a right angle to the unwinding direction.

For example the diameter of the pulling means can be between about 0.5 mm and 1 mm, while the window is of a length and a width of about 5 mm.

If the retraction device is to have a touch-latch functionality (in that case the roller is releasable by an externally applied force acting on the movable furniture part) or if the intention is to ensure that, when a coupling is in an unlocked condition, the pulling means is wound on to the roller, it can be provided that the roller is biased in the unwinding direction by a force storage means.

The force storage means serves on the one hand to wind on the pulling means when the coupling is unlocked. On the other hand the force storage means provides for mechanical tension along the pulling means. By virtue of that arrangement forces exerted on the movable furniture part by a user can be transmitted to the roller by way of the pulling means. A pulling or pushing force applied to the movable furniture part thereby results in a certain rotary movement of the roller, which can be detected by a suitable sensor (for example a rotary potentiometer). The sensor then triggers the electric motor of the retraction device (touch-latch functionality).

Further advantages and details of the invention will be apparent from the Figures and the related specific description. In the Figures:

FIGS. 1 a through 1 c show two perspective views and exploded views respectively of an embodiment of a coupling according to the invention,

FIGS. 2 a through 2 d show a plan view and a respective associated view in section of a coupling according to the invention in various operating positions,

FIG. 3 shows a perspective view of a retraction device with the coupling according to the invention,

FIG. 4 shows a further view of FIG. 3 in a different operating position,

FIG. 5 shows a portion of a furniture body or carcass with a movable furniture part and a retraction device as shown in FIGS. 3 and 4,

FIG. 6 shows a detail view of FIG. 5, and

FIGS. 7 a through 7 c show various views of a retraction process.

FIGS. 1 a and 1 b show two different perspective views of a coupling 1 according to the invention. The coupling 1 has a first coupling portion 2 which can be mounted to a movable furniture part (not shown in FIG. 1). There is also a second coupling portion 3 which in this embodiment has a pin 9 provided with grooves 10 (in FIG. 1 c, only the foremost three grooves are denoted by reference 10, for the sake of enhanced clarity).

It can be seen that the first coupling portion 2 has an opening 4 into which the pin 9 of the second coupling portion 3 can be inserted to different depths (for example between 2 mm and 6 mm). Disposed in front of the opening 4 is a funnel 6 for capturing the pin 9 (see in particular FIGS. 7 a through 7 c).

In this embodiment the second coupling portion 2 is of a substantially two-part configuration, the locking mechanism 5 being arranged between the two parts. The locking mechanism 5 has two pivotably mounted clamping jaws 8 biased in the locking direction by a force storage means 7.

As can be seen in particular from FIGS. 2 a through 2 d which show an insertion process (FIGS. 2 a through 2 c) and an unlocking process (FIG. 2 d) respectively, the two clamping jaws are urged apart against the force of the force storage means 7 during the insertion of the pin 9. That involves slight stretching of the force storage means 7.

In FIG. 2 c the coupling 1 is in the locking condition and the force storage means 7 is pressing the clamping jaws 8 against a single groove 10 on the pin 9.

It can be seen in particular from the sectional view in FIG. 2 d that, when the force exerted by the force storage means 7 is exceeded, the clamping jaws 8 are urged apart by the pin 9, whereby the force storage means 7 is slightly stretched. That means that the second coupling portion 3 can be removed from the first coupling portion 2.

It is essential that, in this embodiment, the pin 9 can be steplessly inserted into the opening 4 to differing extents, due to the plurality of grooves 10. The clamping jaws 8 can lock the pin 9 in any position as the pin 9 is provided with grooves 10 uninterruptedly substantially over its entire axial extent.

FIG. 3 shows a retraction device for a movable furniture part (not shown). The retraction device is provided in a drive 12 which, besides the retraction device, also has an ejection device with an ejection lever 14. The retraction device is disposed in a housing 13 from which the pulling means 11 is extended. The pulling means 11 is connected to the second coupling portion 3 of the coupling 1 shown in the previous Figures.

The housing 13 has a window 14 which is substantially larger than the cross-section of the pulling means 11. That permits compensation in respect of installation tolerances in directions in orthogonal relationship to the illustrated direction of the pulling means 11. Depthwise compensation is ensured by the above-described mechanism so that overall this affords compensation in all directions in space.

FIG. 4 shows the drive 12 used in FIG. 3, wherein the pulling means 11 has been wound completely on to the roller (not shown).

FIG. 5 shows a portion of a furniture body or carcass 15, in which a drawer 16 as the movable furniture part is movably mounted. The first coupling portion 2 of a coupling 1 according to the invention is arranged at the rear side of the drawer 16. In the FIG. 5 condition, the second coupling portion 3 of the coupling 1 according to the invention is connected to the first coupling portion 2 so that the drawer 16 can be moved by the pulling means 11 into its closed final position into the furniture carcass 15. The ejection lever 14 serves to eject the drawer 16 from the furniture carcass 15.

FIG. 6 shows a detail view of FIG. 5.

FIGS. 7 a through 7 c show a situation in which the second coupling portion 3 is arranged eccentrically relative to the first coupling portion 2 due to installation tolerances. It will be seen that nonetheless the funnel 6 permits capture of the pin 9 of the second coupling portion 3. 

1. A retraction device for a movable furniture part comprising a pulling means which can be wound on to a roller, wherein there is provided an electric motor for driving the roller, and a coupling for releasably connecting the movable furniture part to the electric drive, having a first coupling portion intended for fastening to the movable furniture part and a second coupling portion connected to the pulling means, wherein the first coupling portion has an opening for at least partially receiving the second coupling portion, wherein there is provided a locking mechanism by which the first coupling portion can be connected to the second coupling portion in at least two different positions, wherein the second coupling portion is disposed at different depths in the opening in the two different positions.
 2. A retraction device as set forth in claim 1 wherein the locking mechanism releases the connection between the first and second coupling portions upon the attainment of a predetermined separation force.
 3. A retraction device as set forth in claim 2 wherein the predetermined separation force is of equal magnitude for the at least two different positions.
 4. A retraction device as set forth in claim 2 wherein the locking mechanism has two clamping jaws which are biased relative to each other by a force storage means and which clamp the second coupling portion fast in the locking condition.
 5. A retraction device as set forth in claim 1 wherein a pin for insertion into the opening is arranged on the second coupling portion.
 6. A retraction device as set forth in claim 5 wherein arranged on the pin are at least two axially mutually spaced latching positions for the clamping jaws.
 7. A retraction device as set forth in claim 6 wherein each of the latching positions has at least one groove, into which the clamping jaws engage in the locking condition.
 8. A retraction device as set forth in claim 7 wherein the number of grooves into which the clamping jaws engage in the locking condition is the same for each of the latching positions.
 9. A retraction device as set forth in claim 7 wherein the pin has a plurality of adjacent grooves over its axial extent.
 10. A retraction device as set forth in claim 5 wherein a funnel for capturing the pin is disposed in front of the opening.
 11. A retraction device as set forth in claim 1 wherein the second coupling portion is connectable to the pulling means of a retraction device.
 12. A retraction device as set forth in claim 1 wherein the retraction device has a housing in which the roller and the electric motor are arranged.
 13. A retraction device as set forth in claim 12 wherein the housing in the unwinding region of the roller has a window which is substantially larger than the cross-section of the pulling means.
 14. A retraction device as set forth in claim 1 wherein the roller is biased in the winding-on direction by a force storage means. 